Automatic sequential operated valve

ABSTRACT

An automatic four-way valve hydraulically operated for extending and retracting a refuse compaction cylinder, which senses a pressure build-up as the trash is compacted, releasing a pressure responsive detent allowing a spring to drive the valve spool of the primary valve to the return position, allowing the cylinder to retract until it reaches the end of its stroke whereupon a pressure build-up causes a pilot cylinder to move the valve spool to the neutral open center position.

United States Patent Clair [is] 3,680,583 [451 Aug. 1,1972

[ AUTOMATIC SEQUENTIAL OPERATED VALVE [72] Inventor: Gilbert D. Clair,Wichita, Kans.

[73] Assignee: Val-Jae Manufacturing and Supply Company, Inc., Maize,Kans.

22 Filed: Aug. 2, 1971 21 Appl.No.: 168,196

[52] US. Cl. ..137/l06, 137/624.27, 137/624.l8, 91/356 [51] Int. Cl..Fl5b 11/15 [58] Field of Search ..l37/l06, 624.27, 624.18;

[56] References Cited UNITED STATES PATENTS 2,874,720 2/1959 Vahs..l37/624.27

3,638,683 2/1972 Krieter ..l37/624.27

Primary Examiner-Alan Cohan Attorney-Miller & Brown 57 ABSTRACT Anautomatic four-way valve hydraulically operated for extending andretracting a refuse compaction cylinder, which senses a pressurebuild-up as the trash is compacted, releasing a presmre' responsivedetent allowing a spring to drive the valve spool of the primary valveto the return position, allowing the cylinder to retract until itreaches the end of its stroke whereupon a pressure build-up causes apilot cylinder to move the valve spool to the neutral open centerposition.

8 Claims, 2 Drawing Figures PATENTEDAUB um 3.680.583

GILBERT D. CLAIR ATTORNEYS AUTOMATIC SEQUENTIAL OPERATED VALVE SUMMARYOF THE INVENTION The compaction of refuse is normally accomplished byone or a pair of cylinders which move the refuse from the receivinghopper and force it into a compacted state which is more easilytransported and disposed of. A simplified valving arrangement forcontrolling compaction cylinders would be a manually controlled four-waydirectional valve having an open center neutral position. Thedisadvantage with this type of control is that the operator must standbyand hold the valve handle until the refuse is fully compacted and thenshift the valve handle to the reverse position, holding it there untilthe cylinder is completely retracted. This necessitates an operatorstanding at the valve all during the compaction cycle.

Improved automated systems have been developed whereby the operator onlyneeds to initially move the valve handle to the cylinder extendedposition whereupon the other valve movements in the compaction cycle areautomatically accomplished by some form of mechanical actuator. Forexample, as the compacting blade reaches its fully compacted position ittrips a lever arm, which in turn forces the valve spool to the reverseposition. As the compaction cylinder reaches the fully retractedposition, another lever arm is contacted forcing the valve spool back tothe neutral position. Mechanical actuators of this type require a fairlycomplicated linkage system which requires a substantial amount ofmaintenance to properly operate. Due to the lack of trained orexperienced personnel in servicing mobile compaction equipment,manufacturers have been striving to improve the reliability of theirequipment and make it as trouble-free and easily maintainable aspossible. With these purposes in mind, the valve of the presentinvention was designed which utilizes a completely hydraulic servocontrol system without mechanical limits or mechanical actuators. Withthe actuation function of the primary valve being hydraulic, there is noneed for mechanical adjustment or danger of obstruction or malfunctiondue to stray refuse fouling the mechanical mechanism. While there areother hydraulic automatic cycling control circuits on the market, theyinvolve very complex and intricate hydraulic circuitry.

The present invention is a much simplified single spool package typeunit incorporating all of the control circuitry in one unit. Previouslyit has not beenthought practical to actuate a four-way three positionvalve with internal pilot pressure because of the pressure loss when thevalve is shifted to the neutral open center position. The simplifiedvalve design of the present invention utilizes internal pilot pressurecombined with a compressive spring to move the spool across the neutralposition to the reverse flow position. When the cylinder fully retracts,a pressure build-up causes a relief valve to open and a pilot piston todrive the valve spool back to the neutral position. All of the variousautomatic control components are combined into one valve body with theprimary valve, which eliminates numerous connections, hoses and tubing.The usage of the packaging concept with the simplified circuitry of thepresent invention allows for a considerable reduction in assembly time,component weight and overall size of the system. For ease inmaintenance, the overall circuit can be easily repaired by a person withminimal skills replacing the overall valve package.

It is therefore the principal object of the present invention to providea directional valve having a simplified all hydraulic automatic cyclingcontrol circuit.

Another object of the present invention is to provide an automaticcontrol for a four-way three position directional valve which utilizesinternal pilot pressure to actuate the valve.

A further object of the present invention is to provide in the refusehandling field, an automatic hydraulic control system combined in asingle valve body.

For a better understanding of the present invention, together with otherand further objects thereof, reference is had to the followingdescription taken in connection with the accompanying drawings, and itsscope will be pointed out in the appended claims:

FIG. 1 is a schematic diagram of the hydraulic control circuit of thepresent invention; and

FIG. 2 is a longitudinal sectional view of the automatic valve controlmeans attached to a conventional valve having a portion thereof brokenaway.

Referring now to the drawings, and more specifically to FIG. 1, anautomatic valve cycling control system is generally identified byreference numeral 10. The directional control valve 12 which operates aconventional compaction cylinder 17, is a four-way three positionconventional spool valve having a first working position A which extendsthe cylinder, a second working position B retracting the cylinder, andan open center neutral position with fluid locked in the motor ports 11and 13. The valve is manually controlled by push-pull handle 15 whichoverrides compression spring 18 and detent 16. The spring 18 urges thevalve into the B position. Holding the valve in either the neutral Aposition is a pressure responsive detent 16. When pressure builds abovea certain level in port 11, relief valve 20 opens, extending pilotpiston 21 to move the valve spool back to the neutral positionoverriding compression spring 18. The pressure behind pilot piston 21bleeds off through orifice 22, allowing pilot piston 21 to retract dueto the action of spring 35, as shown in detail in FIG. 2.

FIG. 2 is the actual structural drawing of the control system 10diagrammatically illustrated in FIG. 1. Since directional control valve12 is not a part of the present invention, portions of the valve havebeen broken away to conserve space. Valve spool 24 is shown in thecylinder retract position B, with fluid flowing from the cap end ofcylinder 17 through port 13 out return port 25. Attached to the end ofvalve spool 24 is an extension member 26, having a detent 27 for theneutral position and a detent 28 for the cylinder extend position A. Theend of detent piston 30 is normally biased by spring 31 towards adetent. When pressure builds above a certain level on the rod side ofpiston 30, spring 31 is overcome, releasing the detent and allowingcompression spring 18 to move the valve spool 24 to the right. Attachedto the end of extension 26, by means of a screw 32, is a springretaining cap 33. In contact with the end of cap 33 is a pilot piston21, normally spring biased to a retracted position by compression spring35. Orifice 22 in piston 21 allows fluid behind the piston 21 to bleedout through exhaust port 36. The valve motor port 11 of FIG. 1, not seenin FIG. 2, con- OPERATION When the refuse compaction system is not inuse, the valve is positioned in its open center neutral position, asseen in FIG. 1. The valve spool is held in this neutral position bydetent l6 engaging groove 27. To initiate the compaction cycle, theoperator moves the valve handle to position A, the cylinder extendposition, whereupon the spring biased detent 16 engages notch '28. Asthe compaction cylinder 17 approaches the end of its stroke, acompaction blade connected thereto (not shown in the drawing), compactsthe refuse causing the working pressure in motor port 13 to rise. Once apreset'level is exceeded, pressure on the rod side of piston 30overcomes the biasing force of spring3l, releasing the detent 16. As thedetent 16 releases, the compressive force of spring 18 drives the valvespool across the neutral position to the piston retract position B.Thecompaction cylinder 17 then begins to retract due to working pressuresupplied to motor port 1 1. As the compaction cylinder approaches itsfully retracted position, the working pressure in port 11 increases to alevel whereby pressure relief valve 20 opens, allowing fluid to extendpilot piston 21 which drives the valve spool back to the neutralposition.

Since a portion of the primary valve 12, in FIG. 2, is 7 broken away,the working port 1 1 just mentioned is not shown in this figure.Hydraulic line 39, of FIG. 2, would connect working port 11 to pressurerelief valve 20 through port 38. After the valve spool has been drivenby pilot piston 21 to the neutral position, detent groove 27 is engagedand the pressures in the working lines drop to zero. The fluid behindpilot piston 21 bleeds off through drain port 36, through orifice 22, ascompression spring returns pilot piston 21 to its retracted positionwhereby the system is ready for another cycle.

Having described the invention with sufficient clarity to enable thosefamiliar with this art to construct and control system including:

a pressure responsive detent means for holding the valve spool in thefirst working position which.

releases when the working pressure reaches a preset level;

spring means urging the valve spool into the second working positionwhereby as the pressure detent means releases the valve spool is forcedacross the 1 neutral position to the second working position; and

a pilot cylinder means responsive to a preset working pressure in thesecond working position which overcomes the spring means and forces thevalve s It the cut a] sition. 2. iii a irecti on viil i'e as set forthin claim 1,

wherein the pilot cylinder means includes a pressure relief valve whichopens at a set pressure allowing flow to the pilot cylinder.

3. In a directional valve as set forth in claim 1, wherein the pilotcylinder means includes a pressure relief valve which opens at a setpressure allowing flow to the pilot cylinder, a second spring meansurging the pilot cylinder to retract from its extended position andorifice means behind the pilot cylinder venting the fluid to atmosphere,thereby allowing the pilot cylinder to retract from its extendedposition.

4. In a directional control valve as set forth in claim 1, wherein thepressure responsive detent means holds the valve spool in the neutralposition.

5. In a directional control valve as set forth in claim 1, wherein thepressure responsive detent means also holds the valve spool in theneutral position, the spring means having sufficient force once thepressure responsive detent releases from the first working position toforce the valve spool across the detented neutral position to the secondworking position.

6. In a directional control valve as set forth in claim 1, wherein thepressure responsive detent means also holds the valve spool in theneutral position, the spring means having sufficient force once thepressure responsive detent releases from the first working position toforce the valve spool across the detented neutral position to the secondworking position, further including a manual valve spool operator whichcan override either the detent or spring means. I

7. In a directional valve as set forth in claim 1, wherein all of thecomponents of the valve cycling control system are integral in the valvebody forming a single package unit.

8. In a directional valve as set forth in claim 1, wherein the pilotcylinder means includes a pilot piston having an orifice therein ventingto atmosphere and a

1. In a four-way directional valve for use with refuse compactors havinga valve body containing a valve spool bore including two working ports,supply and return ports, a valve spool contained therein defining afirst working position, a reverse flow second working position andmiddle open center neutral position, the improvement comprising anautomatic valve cycling control system including: a pressure responsivedetent means for holding the valve spool in the first working positionwhich releases when the working pressure reaches a preset level; springmeans urging the valve spool into the second working position whereby asthe pressure detent means releases the valve spool is forced across theneutral position to the second working position; and a pilot cylindermeans responsive to a preset working pressure in the second workingposition which overcomes the spring means and forces the valve spool tothe neutral position.
 2. In a directional valve as set forth in claim 1,wherein the pilot cylinder means includes a pressure relief valve whichopens at a set pressure allowing flow to the pilot cylinder.
 3. In adirectional valve as set forth in claim 1, wherein the pilot cylindermeans includes a pressure relief valve which opens at a set pressureallowing flow to the pilot cylinder, a second spring means urging thepilot cylinder to retract from its extended position and orifice meansbehind the pilot cylinder venting the fluid to atmosphere, therebyallowing the pilot cylinder to retract from its extended position.
 4. Ina directional control valve as set forth in claim 1, wherein thepressure responsive detent means holds the valve spool in the neutralposition.
 5. In a directional control valve as set forth in claim 1,wherein the pressure responsive detent means also holds the valve spoolin the neutral position, the spring means having sufficient force oncethe pressure responsive detent releases from the first working positionto force the valve spooL across the detented neutral position to thesecond working position.
 6. In a directional control valve as set forthin claim 1, wherein the pressure responsive detent means also holds thevalve spool in the neutral position, the spring means having sufficientforce once the pressure responsive detent releases from the firstworking position to force the valve spool across the detented neutralposition to the second working position, further including a manualvalve spool operator which can override either the detent or springmeans.
 7. In a directional valve as set forth in claim 1, wherein all ofthe components of the valve cycling control system are integral in thevalve body forming a single package unit.
 8. In a directional valve asset forth in claim 1, wherein the pilot cylinder means includes a pilotpiston having an orifice therein venting to atmosphere and a compressionspring for retracting the pilot piston once extended.